0789

Common Causes

• Failed Rotary encoder 2 (INA-BEARING) producing out-of-range A or B phase voltage
• Contamination or damage inside the encoder affecting the A/B phase outputs
• Damaged encoder cable or connector degrading the signal

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 000A (hex, in XXXX) = The A phase voltage data from the encoder is out of range; YYYY shows the actual A phase voltage value; code 000B (hex, in XXXX) = The B phase voltage data from the encoder is out of range; YYYY shows the actual B phase voltage value
2. 2Read the code on screen: the first four hex digits tell which phase is bad — 000A means the A phase voltage is illegal, 000B means the B phase voltage is illegal; the last four digits show the actual faulty voltage value.
3. 3Lock out machine power and inspect the Rotary encoder 2 (INA-BEARING) connector and cable for looseness, pin damage, coolant ingress, or chafing before condemning the encoder.
4. 4Check the encoder mounting area for coolant, chips, or bearing contamination that could corrupt the A/B phase signals.
5. 5If the wiring and environment are clean, replace Rotary encoder 2 (INA-BEARING) as directed by the manual.
6. 6If the alarm returns with a new encoder, record the alarm number, code and axis object and contact Okuma service.